In market gardening, the soil is still worked with manual implements. For the most part, the person using these implements is usually crouching or kneeling on the soil. This work is repetitive and tiring because the soil has to be prepared after it has been tilled. This includes hoeing, planting, weeding, and harvesting. Moreover, working the soil places the body in positions that are unpleasant. Such positions can cause pain and may, in the long term, result in pathological states, notably in the knees or the back.